Induction heater



30, 1956 c. T. FORSYTH 2,769,075

INDUCTION HEATER Filed May 24, 1954 Fig. 20

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United States Patent INDUCTION HEATER Charles T. Forsyth, Shelbyville, Ind. Application May 24, 1954, Serial No. 431,641

1 Claim. (Cl. 219-1049) This invention relates to an indiction heater and particularly to an improved winding heater element for such a device.

This application is a continuation-in-part of applicants application Serial No. 220,314, filed April 10, 1951.

In the utilization of induction type heaters it has heretofore been proposed to provide a heating device having a magnetic core with a substantially non-heating inducing winding linked with the core and a heater type winding of a secondary type wound on the core and energized by inducement from the inducing winding. Heretofore, considerable difficulty has been experienced in transferring the heat from such an induced winding to distribute the heat for such utilization as may be desired.

The present invention eliminates these difficulties by providing a heating unit comprising a plurality of individual turns each constructed of a plate-like conducting element and providing the plate-like elements of different physical outside dimensions'so that the plates may be assembled in relation to each other with a serrated outer surface or an outer surface having portions of the plates projecting beyond the portions of other plates so that the plates may readily radiate heat or so that the heat may be conducted to a fluid such as air passing through or around the plates.

In order to assemble the plate-like elements in firm relation with each other the plates are provided with an alignment of apertures with a fastening element, such as a bolt, extending therethrough and lugs are provided on the exterior end plates of the stack with means for attaching the same to a magnetic core to prevent vibration or movement thereon.

It is accordingly an object of the invention to provide an improved induction heater.

It is a further object of the invention to provide an induction heater which will readily radiate and distribute heat therefrom.

It is a further object of the invention to provide a secondary winding of the heater type for an induction heater.

It is a further object of the invention to provide an induction heater element having the successive elements thereof of different outside dimensions.

Other objects and many of the attendant advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawing in which:

Figure l is a schematic illustration of a heater for heating air;

Figure 2 is a similar view of a modified heater for heating water;

Figure 3 is an enlarged cross-section view of the assembled heater taken substantially on the plane indicated by the section line. 3-3 of Figure 1;

Figure 4 is an enlarged fragmentary elevation, partially in section of an improved heating element according to the invention;

Figure 5 is a sectional elevation of the modified heater according to the invention;

Figure 6 is a perspective view of one of the larger heating winding elements;

Figure 7 is a similar perspective view of 'one of the smaller heating winding elements; and

Figure 8 is a perspective view of an end heater winding element showing the fastening lugs.

In the exemplification according to the invention the heater is constructed as a container 10 through which a fluid such as air may be passed and in which is placed a heating element indicated generally at 12 and having a magnetic core 14 with which is linked an inducing winding 16 and an induced or heating winding 18. In the construction, such as shown in Figure 1 for heating air, the inducing winding 16 will be placed on one end of the core 14 and preferably will be separated from the heating chamber by a suitable partition 20, preferably of heat insulating material.

When it is desired to utilize the device for heating water, a core 14 will have an inducing winding 16 placed on one end thereof and the heating element 18' will be on the core 14, and linked therewith for submersion in a fluid, such as water. In order to provide the device in water-tight relation a container 22 is provided for one end of the core 14' and the winding 16' will be placed in this container. The container 22 will be provided with a threaded portion 24 for engagement with the walls of a suitable heater device and a water-tight .seal 26 will be provided thereon to prevent the fluid from entering the inducing chamber of the device 22.

In the construction according to the invention the heating element 18 is comprised of a plurality of plate-like winding turns 30 constructed of conducing material herein shown as substantially rectangular in outside formation. The plate-like winding turn 30 is provided with an aperture 32 so that the winding turn 30 may be placed on the core 14 and electrically and magnetically coupled therewith. In addition to the heating winding turns 30 the heating winding turns 34 of a different outside dimension are provided and preferably are substantially of general rectangular shape of the heating winding turn 30 and is provided with an aperture 36 identical with the aperture 32 for mounting the device on the magnetic core 14.

The heating winding elements 30 and 34 are each pro vided with a plurality of apertures 38 and 40 adapted to receive fastening elements such as the bolts 42. When the device is assembled a plurality of heating winding elements 30 will be assembled with a plurality of heating winding elements 34 in any desired formation but preferably in such manner that the heating winding elements 30 of the larger size will be spaced apart by heating winding elements 34 of the smaller size and are shown in Figure 4 one element of the size 30 will be spaced from the next element of the same size by two of the elements of the size of the element 34. Obviously, however, the heating winding elements may be of various sizes so that the devices may be assembled in step formation or an intermediate size may be interposed between alternate smaller sizes so that any desired serrated surface may be produced. For example, in the construction according to Figure 5 alternate large and small heater winding elements have been utilized to provide relatively narrow spaces between the large or extra size heating winding elements 30. Obviously, any desired arrangement of large and small or intermediate size heater wind- .ing elements can be assembled to produce any desired configuration of heater. Normally, this configuration will be associated with the particular purpose in mind as it will be apparent that a fluid, such as water, will readily enter into a narrow space such as the device of Figure 5 or a fluid such as air may be more readily heated by the device such as shown in Figure 4. Even with a particular fluid the velocity with which it is flowing and pressure under which it is maintained may determine a ditferent spacing and arrangement of the plates thanfor another pressure or velocity.

By providing the through fasteners 42 secured by the nuts 44 the heating winding elements may be secured in substantially firm contiguous relation with each other to provide a substantia'llysolid element which will not vibrate because of the induced currents therein. In order to prevent the entire device from vibrating on the core 14 end plates 46 and 48 are provided with upstanding lugs 50 and 52 and 5 and 56 respectively, and each of the lugs 50 to 56 is provided with a threaded aperture 60 in which will be placed clamping fastening devices such as the set scr'ews 62.

In the assemblyof the heater winding element according to the invention, a plurality of plates 30 and 34 together with any necessary intermediate size' plates will be assembled to provide a stack of the necessary size to produce the desiredheating effect and end plates 46 and 48 will be applied thereto with the apertures 38 and 40 of each of the plates in alignmentso that the fastening elements, such as the fastening bolts 42, may be extended therethrough and the plates 34, 30, 46 and 48 rigidly assembled and spaced with respect to each other so that there will be no movement or rattling of the devices. The entire assembly is then placed on the core 14 and locked in position by means of the set screws 62 in the lugs 50 to 56. i

Obviously, the particular assembly of the plates 30 and 34 will be dependent upon the use to be made of the device. When the device is to be used as an air heater it will be'placed in a housing such as the housing and air will be caused to flow across the 'heating element to" not only'be heated by radiation but also by conduction because of contact with the elements the sides of which ment of the plates.

are ekposed because of the construction and arrangep When the device is intended to be used as a water heater the device will be assembled as shown in Figure 2 with a water-tight compartment 22 being sealed into a container of water with the heating elements therein and preferably the heating elements will be spaced so that water will pass therethrough by thermo-syphon action when the plates are heated by the induction.

While for purpose ofexemplification particular embodiment of theinvention has been shown and described according to the best present understanding thereof it will be apparent that various changes and modifications may be made in the construction and arrangement of the parts thereof without departing from the true spirit and scope of the invention.

What is claimed as new is as follows:

A heat generating winding for an induction heater comprising a plurality of plate-like elements of conducting material, each of said plate-like elements having a square aperture adapted, to receive a magnetic core of a square cross section, an end element for said winding, a mounting lug on said end element, said plate-like elements having aligned apertures, therethrough, a fastening device extending through said aligned apertures to retain; said Winding inassembled relation, a fastening device mounted in said lug and adapted to secure said winding on a magnetic core, said plate-likeelements being of differing ei'ifternal dimensions, said. elements being assembled to providea serrated outer-surface."

References Cited in the file of this patent UNITED STATES PATENTS 7 2,171,080 Ely Aug. 29, 1939 2,237,569 Lofgren Apr. 8, 1941 2,432,169 Morgan et a1 Dec. 9, 1947 2,715,171 Williamson Aug. 9, 1955 FOREIGN PATENTS 49,315 De ma kt Sept. 24, 1934 118,677 Australia Mar. 19, 19,42 

